Refutation of Mapping mu-Calculus Onto Second-Order Logic

When mapping mu-calculus onto second-order logic, we show use of the fixpoint operator as untenable. What follows is the effective refutation of mapping mu-calculus onto second-order logic.
Category:Set Theory and Logic

Refutation of Completeness for Non-Deterministic Logic

We show that the four-valued, non-deterministic semantics for modal logic are not complete. The demonstration uses contradictions based on Carnielli's paraconsistent logic. What follows is that infinite non-deterministic matrices are by definition incomplete.
Category:Set Theory and Logic